<!DOCTYPE HTML>
<html>
<head>
  <title>Test the offset property on AudioBufferSourceNode</title>
  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
  <script type="text/javascript" src="webaudio.js"></script>
  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
</head>
<body>
<pre id="test">
<script class="testbody" type="text/javascript">

var fuzz = 0.3;

if (navigator.platform.startsWith("Mac")) {
  // bug 895720
  fuzz = 0.6;
}

SimpleTest.waitForExplicitFinish();
addLoadEvent(function() {
  var samplesFromSource = 0;
  var context = new AudioContext();
  var sp = context.createScriptProcessor(256);

  sp.onaudioprocess = function(e) {
    samplesFromSource += e.inputBuffer.length;
  }

  var buffer = context.createBuffer(1, context.sampleRate, context.sampleRate);
  for (var i = 0; i < context.sampleRate; ++i) {
    buffer.getChannelData(0)[i] = Math.sin(440 * 2 * Math.PI * i / context.sampleRate);
  }

  var source = context.createBufferSource();

  source.onended = function(e) {
    // The timing at which the audioprocess and ended listeners are called can
    // change, hence the fuzzy equal here.
    var errorRatio = samplesFromSource / (0.5 * context.sampleRate);
    ok(errorRatio > (1.0 - fuzz) && errorRatio < (1.0 + fuzz),
       "Correct number of samples received (expected: " +
       (0.5 * context.sampleRate) + ", actual: " + samplesFromSource + ").");
    SimpleTest.finish();
  };

  source.buffer = buffer;
  source.connect(sp);
  source.start(0, 0.5);
});

</script>
</pre>
</body>
</html>
